Finding the Fourth Proportional to 1,165.79, 1,608.89 and 641.93

Step by Step Solution

1. Step 1: Write the proportion equation
   1,165.79 : 1,608.89 = 641.93 : x
2. Step 2: Convert to fraction form
   1,165.79/1,608.89 = 641.93/x
3. Step 3: Cross multiply
   1,165.79x = 1,608.89 × 641.93
4. Step 4: Simplify right side
   1,165.79x = 1,032,783.50
5. Step 5: Solve for x
   x = 1,032,783.50/1,165.79
6. Step 6: Final answer
   x = 885.91